John Pitcairn, owner of “Cairnwood,” began his career with the Pennsylvania Railroad in western Pennsylvania, then shifted to manufacturing glass with the formation of Pittsburgh Plate Glass. His choice of architects, New York City's Carrère and Hastings, was adventurous—they had just finished the great hotels in St. Augustine, Florida, but had not yet received such monumental commissions as the New York Public Library, and thus were not well known in Philadelphia. Here they combined the light palette of yellow brick and limestone of the late nineteenth century and the light touch and historic French detail of Richard Morris Hunt in the Philadelphia countryside. The plan is an odd combination of Hunt's grand mansions and Shingle Style informality with the main block eroded to bring light and ventilation into each room and opening on to exterior terraces set against an angled service wing.